Rectifier circuits



July 26,1932. vK. C BLAcK 1,869,089

RECTIFIER CIRCUITS Fil'ed April 23, 1930 fw 10g; .6 fff'f i @l C s J dttozue xrv.

manici Patented 'July 26, 1 932 '1 i lUNITED STATES PATENT ori-fles.

INOX CHARLTON BLACK., F BOONTON, JEBSEY,`ASSIGNOB, BY MESNE ASSIGN- MENTS, TO RADIO CORPORATION OF AMERICA, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE Application led April 23,

single rectifier stage. A further object is to provide a rectifier stage including a multielement vacuum tube, the circuit arrangevmerits being such that the tube functions both -as anamplifier. and as a diode rectifier. More particularly, an object is to provide a rectier stage of the type stated in which the tube functions as a diode rectifier and as an amplifier for the rectified signal.

These and-.rzother objects of the invention will be apparent from the following specification, when taken with the accompanying drawing in which: g

Figs. l to inclusive are circuit diagrams illustrating different 'embodiments of the invention.

In accordance with the present invention,

the rectifier stage includes a -multi-element vacuum tube and circuit elements so. as

`sociated therewith that one element coop crates with the cathode to function as a diode rectifier, and a plurality of other elements cooperate with the cathode to function as an amplifier.-

As shown diagrammatically in Figs. 1 and 2, the vacuum tube may be a tetrode of the known commercial types in which there are a plurality of cylindrical elements surrounding and co-axial with the cathode. In the circuit of Fig. 1,'the tuned input circuit 1 is connected between 'the grid G2 and the cathode C, a grid condenser 2 and shunt resistance 3 being arranged between the tuned l circuit and the grid. Aradio frequency choke 4 and' radio frequency by-pass condenser 5 are connected between the grid G2 and the cathode, the junction of the choke`4 and con I denser 5 beingconnected to the inner grid RECTIFIER CIRCUITS 1930. serial no. 446,755. I

G1. The plate P is connected to the cathodel yfour-element amplifier.

c RElSSUED through an impedance, such as the primary of an audio frequency transformer 6, and a source 7 of plate current. A grid bias is applied to grid G1 by battery 8 and the grid resistance 9; this bias voltage being blocked.

from grid G2 by the condenser 10.

The grid G2 and cathode C are at substantially the, same direct current potential and operate as a diode rectifier for the signal volt-v age impressed across the tuned circuit 1. The

rectified voltage resulting from the triode rectification is impressed across the inner grid G1 and cathode (J by means of the radio frequency choke 4. AThe by-pass condenser 5 substantially prevents any radio frequency potential difference between the inner grid G1 andthe cathode. The cathode, inner grid and plate act as a triode for the amplification of theaudio frequency voltage resulting from` the diode rectification. Though the grid' G2 is positioned in the electron stream between the cathode C and plate P, the radio frequency voltage on this grid has a comparatively small effect upon the electron stream since the. grid G2 is located outside of the amplifier control grid G1.

As lshown in Fig. 2, the plate P may act as one element of the diode rectifier. The rectified voltage is then impressed upon the inner grid G1 and the amplified audio output is developed between the outer grid G2 and the cathode. The other elements of the circuit may be identical with the corresponding elements of the Fig. l circuit.

The pentode rectifier circuit of Fig. 3 1s similar to that of the Fig. 1 circuit and corret spondin elements have been identified by the same re erence numerals as those employed in Fig. 1.'- The essential difference in the Fig. 3 circuit is the introduction of the screen grid G2 between the diode rectifier id G3 and the audio frequenc control grid 1.

As shown in igs. 4 and 5, the plate P may serve as the anode of the diode rectifier. In the Fig. 4 circuit, the audio frequency voltage is impressed upon the intermediate grid G2, the inner grid G1 is a space charge rid and the outer grid G serves as the ano e of the In the Fig. 5 circuit, the audio frequency response of the diode is impressed upon the inner grid G1, the gridG2 serves as a space charge grid and the outer1 grid (Si3 is the anode element of the amplifier.

As compared with the usual circuit rectiiication systems in which the carrier voltage is impressed upon the innergrid element, the invention provides linear rectification over a wide range of impressed signal voltages. The customary grid circuit 2rectifier overloads at relatively lowy signal voltages when the radio frequency voltage swing becomes large enough to cause plate rectification in opposition to ,the grid rectification. As compared with the usual diode rectifier, the invention combines linear rectification and one stage of amplification.

As stated above, the multi-element tubes may be of the usual commercial construction, but it is possible to employ tubes having a diode element that is located outside of the electron stream established between the cath- 0de and the amplifier anode. A tube construction of this type is described and claimed in my copending application Serial Number 446,098, med April 21, 1930.

I claim:

1. The combination with a vacuum tube having a cathode and a plurality of elements, of a circuit including a grid condenser and l leak between said cathode and one of said elements, means for impressing a carrier wave signal upon said circuit, means for impressing the rectified voltage developed in said circuit between another element and said cathode, and an output circuit between said cathode and a third -tube element.

2. The combination with a vacuum tube having a cathode and a plurality of elements serially arranged in the electron stream established by said cathode, of a diode -rectifier circuit connected between said cathode and an element s aced from said cathode, a radio frequency c oke connecting said diode element to an element between the same and said cathode, a radio frequency by-pass condenser betweensaid cathode and said second element, and an voutput circuit between said cathode and a third element which is more remote from said cathode than said second element.

8. A linear rectifier and amplifier comprising a tube provided with a cathode, a positive electrode, and a plurality of intermediate grid elements, a diode rectifier circuit connected between the cathode and a grid, an audio Iinput circuit, coupled to said rectifier circuit, between said cathode and a second grid, und an audio output circuit connected between said cathode and positive electrode.

4. A linear rectifier and amplifier comprising a tube provided with a cathode, a positive electrodo, and a plurality of intermediate grid elements, a diode rectifier circuit connmetcd between the cathode and a grid, relnote from the cathode, an audio input circuit, coupled to said rectifier circuit, between said cathode and a second grid, and an audio output circuit connected between said cathode and positive electrode. Y

5. A linear rectifier and amplifier comprising a tube provided with a cathode, a positive electrode, and a plurality of intermediate grid elements, `a diode rectifier circuit connected between the cathode and a grid, an audio input circuit, coupled to said rectifier circuit, between said cathode and a second grid, disposed between said cathode and first grid, and an audio output circuit connected between said cathode and positive electrode.

6. A linear rectifier and amplifier comprising a tube provided with a cathode, a positive electrode, and a plurality of intermediate grid elements, a diode rectifier circuit connected between the cathode and a grid, remote from the cathode, an audio input circuit, coupled to said rectifier circuit, between said cathode and a second grid, disposed between said cathode and first grid, and an audio output circuit connected between said cathode and positive electrode.

7. The combination with a vacuum tube having a cathode and a plurality of elements, of a circuit including a grid condenser and leak between said cathode and one of said elements, means for impressing a carrier wave signal upon said circuit, means for impressing the rectified voltage developed in said circuit between another element and said cathode, and an output circuit between said cathode and a third tube element, said third tue element comprising the anode of said tu e.

8. Thecombination with a vacuum tube having a cathode and a plurality of elements, of acircuit including a rid condenser and leak between said catho e and one of said elements, means for impressing a carrier wave signal upon said circuit, means for impressing the rectified voltage developed in said circuit between another element and said cathode, and an output circuit between said cathode and a third tube element, said first tube element comprising the anode of said tu e.

9. The combination with a vacuum tube having a cathode and a plurality of elements,"

energy, a combined detector-amplifier comprising a tube having its cathode and a remote cold electrode coupled to a diode rectifier circuit, the source being connected to the circuit, an audio amplifier input circuit, coupled to said rectifier circuit, and connected between the cathode andV another cold electrode, and an audio output circuit connected between the cathode and a highly positive cold electrode. A

11. In combinatiom'a combined detectoramplier comprising a'tube having its cathode and a remote cold electrode coupled to 2 serve'as a diode rectifier circuit, means for impressing high freqluency si al currents on said circuit, an au io ampli er input cir-s,

cuit including a capacitor having one terminal connected to said rectifier circuit and its other terminal connected to another cold electrode, a third cold electrode, andan audio out ut circuit connected between the cathode andp said third named electrode.

12. In combination, a combined detectoramplifier comprising atnbe having its cathode and a remote cold electrode coupled to serve as a diode rectifier circuit, means for impressing .high frequency si nal currents on said circuit, an audioy ampl' er input circuit including a capacitor having one terminal connected to said rectiercircuit and its other terminal connected to another cold electrode, a third cold electrode, and an audio output circuit connectedbetween the cathode andsaid third named electrode vand a path including a Abiasing source connected between said second cold'electiode and said cathode.

13. In combination, a combined detectoramp'lifier'c'omprising a tube having its cathode and a-'remote cold electrode coupledto serve as a dioderectifier circuit, means for impressing high frequency signal currents on connecte said circuit, an audio ampli er input circuit including a capacitor having one terminal connected to said rectifier circuit through a high fre uency choke and its other terminal d to another cold electrode, a third cold electrode, and an audio out ut circuit connected between the cathode an said third named electrode.

14. In combination, a combined detectoramplifier comprising a tube having its cathode and a remote cold electrode coupled to serve as a diode rectifier circuit, means for impressing high frequency si al currents on said circuit, an audio'ampli er input circuit including a capacitor havingv one terminal connected to said rectifier circuit and its other terminal connected to another cold electrode, a third cold electrode, and an audio output circuit connected'between the cathode and said third named electrode, said remote electrode being the anode of the tube.

15. In combination, a combined detectoramplifier comprising a tube having its cathode and aremote cold electrode coupled to impressing high frequency si serve as a diode rectifier circuit, means comprisinigr a resonant circuit for impressing igh y equency slgnal currents on sald circuit, an audio amplifier input circuit including a capacitor having one terminal connected to said rectifier circuit and its other terminal connected to another cold electrode, a third cold electrode, and an audio output circuit connected between the cathode and said third named electrode.

16. In combination, a combined detectoramplifier comprising a tube having its cathode'. and a remote cold electrode coupled to serve as a diode rectifier circuit, means for al currents on said circuit, an audio ampli er input circuit includin a capacitor having one terminal connecte to said rectifier circuit and .its other terminal connected to another cold electrode,

a third cold electrode, and an audio output circuit connected between.- the cathode and said third named electrode and a positive cold electrode disposed between the second and third cold electrodes.

17. In combination, a combined detectoramplifier comprising a tube having its cathode and a remote cold electrode coupled to serve as a diode rectifier circuit, means for impressing high frequency si nal currents on said circuit, an audio ampli er input circuit including a capacitor having one terminal connected to said rectifier circuit and its other terminal connected to another cold electrode, a third cold electrode, an audio output cir-` cuit connected between the cathode and said third named electrode and a positive auxiliary electrode disposed between the cathode and said second cold electrode.

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